Clinical Outcomes of Myocardial Bridging versus No Myocardial Bridging in Patients with Apical Hypertrophic Cardiomyopathy.

OBJECTIVE

To determine the prevalence and clinical effects of myocardial bridging (MB) in patients with apical hypertrophic cardiomyopathy (AHCM).

METHODS

Angiograms from 212 AHCM patients were reviewed to identify MB. The patients were classified into 2 groups: AHCM with and AHCM without MB. We reviewed patient records on cardiovascular (CV) risk factors, symptoms, CV events, and CV mortality.

RESULTS

In all, 60 patients with MB and 100 without MB were included. Rates of angina (61.7 vs. 40%; p = 0.008), mimicking non-ST-segment elevation myocardial infarction (15 vs. 3%, p = 0.013), and Canadian Cardiovascular Society class III/IV angina (18.3 vs. 4%; p = 0.003) were higher in patients with MB than in those without. Mean follow-up periods (65.5 ± 50.5 vs. 64.4 ± 43.6 months, p = 0.378) and CV mortality (3.3 vs. 1%; p = 0.652) were similar in the 2 groups. Kaplan-Meier estimates demonstrated that CV event-free survival rates were lower in patients with MB than in those without (71.7 vs. 88%; p = 0.022). MB, late gadolinium enhancement, and female sex were independent risk factors for CV events in a multivariate Cox regression analysis adjusted for other risk factors.

CONCLUSION

More serious symptoms and a higher risk of CV events were observed in AHCM patients with MB than in those without MB. CV mortality was similar in these 2 groups.